Remain in inQuotes state for escaped double-quotes (#366)

Author: damluk

CHANGELOG.md

@@ -7,6 +7,7 @@
 * BUGFIX: fix log level coloring when no custom rules are configured. See [#347](https://github.com/VictoriaMetrics/victorialogs-datasource/issues/347).
 * BUGFIX: respect adhoc filters variables. See [#361](https://github.com/VictoriaMetrics/victorialogs-datasource/issues/361)
 * BUGFIX: fix issue with concurrent map writes when performing multiple requests to the datasource. See [this issue](https://github.com/VictoriaMetrics/victoriametrics-datasource/issues/363)
+* BUGFIX: fix a parsing issue with quoted characters inside `_stream` fields. See [#365](https://github.com/VictoriaMetrics/victorialogs-datasource/issues/365).
 
 ## v0.19.3
 

pkg/utils/stream_fields_parser.go

@@ -80,25 +80,30 @@ func splitStreamsToFields(streamFields string) []string {
 	var fields []string
 	var currentField strings.Builder
 	var inQuotes bool
+	var escaping bool
 	var expectingComma bool
 
 	for i := 0; i < len(streamFields); i++ {
 		char := streamFields[i]
 
 		if char == '"' {
-			inQuotes = !inQuotes
+			if !escaping {
+				inQuotes = !inQuotes
+			}
 			currentField.WriteByte(char)
 
 			// After closing quote, we should be expecting a comma for field separation
 			if !inQuotes {
 				expectingComma = true
 			}
+			escaping = false
 		} else if char == ',' && expectingComma {
 			// Only split on commas that follow a closing quote
 			field := strings.TrimSpace(currentField.String())
 			fields = append(fields, field)
 			currentField.Reset()
 			expectingComma = false
+			escaping = false
 		} else {
 			currentField.WriteByte(char)
 
@@ -107,6 +112,7 @@ func splitStreamsToFields(streamFields string) []string {
 			if expectingComma && char != ' ' {
 				expectingComma = false
 			}
+			escaping = char == '\\' && !escaping
 		}
 	}
 

pkg/utils/stream_fields_parser_test.go

@@ -368,4 +368,104 @@ func TestParseStreamFields(t *testing.T) {
 		},
 	}
 	f(o)
+
+	// Escaped double-quotes
+	o = opts{
+		streamFields: `{peculiar="\"",job="loki.source.journal.read"}`,
+		want: []StreamField{
+			{
+				Label: "peculiar",
+				Value: `"`,
+			}, {
+				Label: "job",
+				Value: "loki.source.journal.read",
+			},
+		},
+	}
+	f(o)
+
+	// Escaped double-quotes
+	o = opts{
+		streamFields: `{peculiar="\"",job="loki.source.journal.read",name="value"}`,
+		want: []StreamField{
+			{
+				Label: "peculiar",
+				Value: `"`,
+			}, {
+				Label: "job",
+				Value: "loki.source.journal.read",
+			}, {
+				Label: "name",
+				Value: "value",
+			},
+		},
+	}
+	f(o)
+
+	// Escaped backslash
+	o = opts{
+		streamFields: `{peculiar="\\",job="loki.source.journal.read"}`,
+		want: []StreamField{
+			{
+				Label: "peculiar",
+				Value: `\`,
+			}, {
+				Label: "job",
+				Value: "loki.source.journal.read",
+			},
+		},
+	}
+	f(o)
+
+	// Escaped backslash
+	o = opts{
+		streamFields: `{peculiar="\\",job="loki.source.journal.read",name="value"}`,
+		want: []StreamField{
+			{
+				Label: "peculiar",
+				Value: `\`,
+			}, {
+				Label: "job",
+				Value: "loki.source.journal.read",
+			}, {
+				Label: "name",
+				Value: "value",
+			},
+		},
+	}
+	f(o)
+
+	// Escaped tab
+	o = opts{
+		streamFields: `{peculiar="\thello",job="loki.source.journal.read"}`,
+		want: []StreamField{
+			{
+				Label: "peculiar",
+				Value: "\thello",
+			}, {
+				Label: "job",
+				Value: "loki.source.journal.read",
+			},
+		},
+	}
+	f(o)
+
+	// Escaped tab
+	o = opts{
+		streamFields: `{peculiar="\thello",job="loki.source.journal.read",name="value"}`,
+		want: []StreamField{
+			{
+				Label: "peculiar",
+				Value: "\thello",
+			}, {
+				Label: "job",
+				Value: "loki.source.journal.read",
+			}, {
+				Label: "name",
+				Value: "value",
+			},
+		},
+	}
+	f(o)
+
 }